@atlaskit/top-layer

Low-level top-layer primitives using the native Popover API (popover="auto") and <dialog> element.

Popover

The primary primitive: a <div> with the popover attribute, plus a small lifecycle (animations, role-based focus management, light-dismiss, nested-focus restoration). It does not know about placement — compose it with the useAnchorPosition hook when you need anchor-positioned content.

import { useRef } from 'react';
import { slideAndFade } from '@atlaskit/top-layer/animations';
import { getAriaForTrigger } from '@atlaskit/top-layer/get-aria-for-trigger';
import { Popover } from '@atlaskit/top-layer/popover';
import { PopoverSurface } from '@atlaskit/top-layer/popover-surface';
import { usePopoverId } from '@atlaskit/top-layer/use-popover-id';
import { useAnchorPosition } from '@atlaskit/top-layer/use-anchor-position';

function MyPopup({ isOpen, onClose }: { isOpen: boolean; onClose: () => void }) {
	const triggerRef = useRef<HTMLButtonElement>(null);
	const popoverRef = useRef<HTMLDivElement>(null);
	const popoverId = usePopoverId();

	useAnchorPosition({
		anchorRef: triggerRef,
		popoverRef,
		placement: { axis: 'block', edge: 'end', align: 'start' },
	});

	return (
		<>
			<button
				ref={triggerRef}
				onClick={() => popoverRef.current?.togglePopover()}
				{...getAriaForTrigger({ role: 'dialog', isOpen, popoverId })}
			>
				Open
			</button>
			<Popover
				ref={popoverRef}
				id={popoverId}
				role="dialog"
				label="Settings"
				isOpen={isOpen}
				animate={slideAndFade()}
				onClose={onClose}
			>
				<PopoverSurface>Content here</PopoverSurface>
			</Popover>
		</>
	);
}

• Focus restoration is automatic. The browser handles it for outermost popovers; Popover snapshots document.activeElement on open and restores it on close for nested cases.
• For default overlay styling (background, shadow, border-radius), wrap content in PopoverSurface from @atlaskit/top-layer/popover-surface.
• For trigger-less or custom-positioned UI (flag, tooltip, react-select menu portal), use Popover on its own without useAnchorPosition.

Dialog

Compound component for modal dialogs using the native <dialog> element with .showModal().

{
	isOpen && (
		<Dialog onClose={handleClose} width="medium">
			<Dialog.Content>
				<Dialog.Surface>
					<Dialog.Header>
						<Dialog.Title>Heading</Dialog.Title>
						<Dialog.CloseButton />
					</Dialog.Header>
					<Dialog.Body>Content</Dialog.Body>
					<Dialog.Footer>Actions</Dialog.Footer>
				</Dialog.Surface>
			</Dialog.Content>
		</Dialog>
	);
}

Animations

Both Popover and Dialog support CSS-based entry/exit animations via the animate prop. Animations use @starting-style for entry and allow-discrete on display/overlay for exit — no JavaScript animation coordination required.

Presets are available from @atlaskit/top-layer/animations:

import {
	// Popover presets
	slideAndFade,
	fade,
	scaleAndFade,
	// Dialog presets
	dialogSlideUpAndFade,
	dialogFade,
} from '@atlaskit/top-layer/animations';

Popover animation

Pass a preset to Popover:

import { slideAndFade } from '@atlaskit/top-layer/animations';
import { Popover } from '@atlaskit/top-layer/popover';

const animation = slideAndFade();

<Popover animate={animation} role="dialog" label="My popover">
	Content
</Popover>;

For overlay styling (background, shadow, border-radius), wrap children in PopoverSurface from @atlaskit/top-layer/popover-surface.

Available popover presets:

• slideAndFade({ distance? }) — directional slide + opacity (default for tooltip)
• fade — simple opacity transition
• scaleAndFade — scale from 0.95 + opacity (suitable for menus/dropdowns)

Dialog animation

Pass a preset to Dialog.Content:

import { dialogSlideUpAndFade } from '@atlaskit/top-layer/animations';

const animation = dialogSlideUpAndFade();

<Dialog.Content animate={animation}>
	<Dialog.Surface>...</Dialog.Surface>
</Dialog.Content>;

Available dialog presets:

• dialogSlideUpAndFade({ distance? }) — slide up + opacity with backdrop fade (matches legacy modal entrance)
• dialogFade — simple opacity + backdrop fade

Progressive enhancement

Browsers without @starting-style support will show/hide elements instantly — no broken state. The prefers-reduced-motion: reduce media query sets all transition durations to 0s.

Accessibility

Browser tests in __tests__/playwright/ verify the following WCAG 2.2 success criteria. See notes/goals/accessibility-criteria.md and notes/decisions/accessibility-audit-report.md for details.

| A11y criterion | Browser test | | ------------------------------------ | ------------ | | 1.3.1 Info and Relationships | ✓ | | 1.3.2 Meaningful Sequence | ✓ | | 2.1.1 Keyboard | ✓ | | 2.1.2 No Keyboard Trap | ✓ | | 2.4.3 Focus Order | ✓ | | 2.4.7 Focus Visible | ✓ | | 2.4.11 Focus Not Obscured | ✓ | | 3.2.1 On Focus | ✓ | | 4.1.2 Name, Role, Value | ✓ | | 4.1.3 Status Messages | ✓ | | Background inertness (modal dialogs) | ✓ | | Close reasons (Dialog) | ✓ |

Documentation

See notes/ for project documentation, architecture decisions, migration records, and audit reports. The notes/README.md provides a full index, including current migration status and links to notes/decisions/migration-roadmap.md.